Qac
abbr. quaternary ammonium compound 季铵化合物（杀菌剂）
🗣️ 情景例句
Something old.
旧的东西。
I will go out with him is he asks me.
我会和他出去，假如他要求我的话。
but of accumulated knowledge applied to practical life.
而是积累起来的知识应用到实际生活中的结果。